Technical Field
The present invention relates to a winding apparatus for winding up paper into a paper roll.
Background Art
When printing paper such as a continuous web of paper having been printed on is wound up onto a paper winding shaft (winding core) to form a paper roll thereon, a failure to apply a sufficient amount of tension to the paper gives rise to an inconvenience of resulting in a loosely wound-up paper roll, whereby a paper portion on its peripheral side may axially slip out of position of a paper portion on its core side or in its transport the paper may become unwound.
Especially when printed on by an ink jet recording apparatus, the printed paper insufficiently dried and having a plenty of water content left contained therein becomes softer and more pliable, making itself prone to wrinkle immediately before it is wound up. Since the paper then fails to be adequately wound up intensely or under a sufficient amount of tension, there tends to arise the inconvenience mentioned above.
A winding apparatus is disclosed in JP H05-077994 A in which an attempt is made to prevent the occurrence of winding wrinkles when paper is wound up, by applying an increased tension thereto.
In this winding apparatus as shown in FIG. 1, paper (a film) 1 is guided by a first and a second free roll 2a and 2b and a winding guide arm 5 which is swingably supported on an swing support member 3 and which is swung thereon with a cylinder actuator 4, the arm 5 having a touch roll 6 rotatably supported at its front free end. While the paper 1 is held pressed by the touch roll 6 against the winding core 7, the winding core 7 is rotated, thereby winding up the paper 1 under an added tension into a paper roll 8 on the winding core 7.
In the conventional winding apparatus cited above, an attempt has been made to avoid the occurrence of a paper winding wrinkle by shortening the distance between the second free roll 2b and the touch roll 6 along a paper winding path, e. g. to not more than 500% of a width of the paper 1.
However, the free roll 2b in the apparatus of FIG. 1 is positioned not to interfere with the paper roll 8 having the paper 1 wound up to its maximum diameter, i.e. with a paper roll 8 increased in diameter to a maximum. With the paper roll 8′ becoming larger in its maximum diameter, the distance between the second free roll 2b and the touch roll 6 along the paper winding path may become longer, whereby the free roll 2b may not be positioned so as to approach to the touch roll 6 by 500% or less of the width of paper 1, possibly bringing about a winding wrinkle. Note that the distance between the second free roll 2b and the touch roll 6 along the paper winding path varies with the diameter of the paper roll 8 and becomes longer as the paper roll 8 grows larger in diameter.
Also, since the arm 5 supporting the touch roll 6 is positioned at the side of the winding core 7 which is opposite to the second free roll 2b, the paper roll 8 having the paper wound up to the maximum diameter may, when moved downstream for its removal and restoring the winding core 7, be obstructed by the touch roll 6 and the arm 5, making the removing and restoring operation awkward to perform.
Further, the apparatus is not adapted at all to guide the paper obversely and reversely and so wind it up switchably.
It is an object of the present invention to provide a winding apparatus that can solve such problems as mentioned above.